In wellbore operations, tubing strings are used having walls with one or more ports extending therethrough. The ports permit fluid access from the tubing string inner diameter and the tubing string's outer surface, which is open to the wellbore.
A kobe plug, also called a break-off plug or a kobe, is closure that can be mounted at its base over a port with a cap portion extending from the base. A channel extends through the base into the cap, but is closed off at the cap. The cap portion protrudes from the port and is removable from the base to open the port to fluid flow through the channel. A kobe plug is installed in a tubular housing, called a kobe sub, that can be installed into a wellbore tubing string. The cap portion of the kobe plug often protrudes into the inner bore of the tubing string.
Generally, the kobe plug is removed by running a tool through inner bore of the string to break off the cap portion. The tool may be a drop bar, a cutter tool, etc. In some embodiments, there they may be concern of a cap being inadvertently removed by abutment by a treatment string or a tool, as it is passed thereby.
In some other embodiments, the cap portion, when removed from its port, is loose and can interfere with string operations. Such loose portions of the cap can, for example, jam in tools or in string structures or can obstruct ports.